One-Pot Sequential Stereoselective Synthesis of Trisaccharide (Glc(beta)1-6Glc(beta)1-6Glc) by Promotion of Trityl Tetrakis(pentafluorophenyl)borate Catalyst

A one-pot synthesis of trisaccharides was successfully carried out by combination of two types of the trityl tetrakis (pentafluorophenyl)borate catalyzed stereoselective glycosylation reactions. Selective activation of a glycosyl phenyl carbonate in the presence of a thioglycoside allows two successive glycosyl coupling in one-pot manner to afford several protected trisaccharides, Glc(beta)1-6Glc(beta)1-6Glc, in good to high yields.